FIELD OF THE INVENTION
The invention relates to a stapler having a magazine and staples guided therein under spring tension and fed thereby to an ejection channel. The staple located in the region of the ejection channel is thrust out of the ejection channel and through the material to be stapled by a thrust blade. The legs of the staple are bent when the thrust blade ejects the staple against a stapling material support having a slit-like perforation and an apparatus for flat-clinch stapling, both of which are located below the ejection channel.
In flat-clinched stapling, staple legs penetrate vertically through the material to be stapled and, subsequently, are bent over at right angles. In other words, the free lengths of the legs are bent over virtually parallel into the plane of the material to be stapled.
U.S. Pat. No. 5,516,025 to Eriksson discloses a generic type stapler described above. The stapler possesses a stapling material support with a slit-like perforation having n associated apparatus for flat-clinch stapling. These staplers have proved their value, as have the staplers whose stapling plates have shaped stampings on their upper sides for legs of the ejected staples. Such a stapler is disclosed, for example, in German Published, Non-Prosecuted Patent Application 21 19 484.
The configuration has a disadvantage that the staple legs are given a curved shape in the stamping after passing through the stapling material. As a result of their shape, the legs bent over below the stapled material protrude, creating undesirable protrusions when the stapled material is placed in a file. Although the defect is absent in flat-clinch stapling, flat-clinch stapling is unsuitable for the stapling material of relatively low thickness (i.e., a few sheets of paper) because the risk of unintentional staple release cannot be eliminated.